* [PATCH v2] mips: Use builtins for ffs and ffsll
@ 2024-02-06 8:34 Junxian Zhu
2024-02-13 7:45 ` Maxim Kuvyrkov
0 siblings, 1 reply; 2+ messages in thread
From: Junxian Zhu @ 2024-02-06 8:34 UTC (permalink / raw)
To: libc-alpha; +Cc: Junxian Zhu
From: Junxian Zhu <zhujunxian@oss.cipunited.com>
__builtin_ffs{,ll} basically on __builtin_ctz{,ll} in MIPS GCC compiler.
The hardware ctz instructions were available after MIPS{32,64} Release1. By using builtin ctz. It can also reduce code size of ffs/ffsll.
Checked on mips o32. mips64.
Signed-off-by: Junxian Zhu <zhujunxian@oss.cipunited.com>
---
sysdeps/mips/math-use-builtins-ffs.h | 3 +++
1 file changed, 3 insertions(+)
create mode 100644 sysdeps/mips/math-use-builtins-ffs.h
diff --git a/sysdeps/mips/math-use-builtins-ffs.h b/sysdeps/mips/math-use-builtins-ffs.h
new file mode 100644
index 0000000000..2ab6a03a16
--- /dev/null
+++ b/sysdeps/mips/math-use-builtins-ffs.h
@@ -0,0 +1,3 @@
+#include <sysdep.h>
+#define USE_FFS_BUILTIN (__mips_isa_rev >= 1)
+#define USE_FFSLL_BUILTIN (__mips_isa_rev >= 1)
--
2.43.0.windows.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v2] mips: Use builtins for ffs and ffsll
2024-02-06 8:34 [PATCH v2] mips: Use builtins for ffs and ffsll Junxian Zhu
@ 2024-02-13 7:45 ` Maxim Kuvyrkov
0 siblings, 0 replies; 2+ messages in thread
From: Maxim Kuvyrkov @ 2024-02-13 7:45 UTC (permalink / raw)
To: Junxian Zhu; +Cc: GNU C Library, Adhemerval Zanella Netto
> On Feb 6, 2024, at 12:34, Junxian Zhu <zhujunxian@oss.cipunited.com> wrote:
>
> From: Junxian Zhu <zhujunxian@oss.cipunited.com>
>
> __builtin_ffs{,ll} basically on __builtin_ctz{,ll} in MIPS GCC compiler.
> The hardware ctz instructions were available after MIPS{32,64} Release1. By using builtin ctz. It can also reduce code size of ffs/ffsll.
>
> Checked on mips o32. mips64.
>
> Signed-off-by: Junxian Zhu <zhujunxian@oss.cipunited.com>
> ---
> sysdeps/mips/math-use-builtins-ffs.h | 3 +++
> 1 file changed, 3 insertions(+)
> create mode 100644 sysdeps/mips/math-use-builtins-ffs.h
Please CC reviewers of previous patch versions -- Adhemerval in this case.
LGTM.
Do you have commit access? If not, please ask Adhemerval to merge your patch.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>
Thanks!
>
> diff --git a/sysdeps/mips/math-use-builtins-ffs.h b/sysdeps/mips/math-use-builtins-ffs.h
> new file mode 100644
> index 0000000000..2ab6a03a16
> --- /dev/null
> +++ b/sysdeps/mips/math-use-builtins-ffs.h
> @@ -0,0 +1,3 @@
> +#include <sysdep.h>
> +#define USE_FFS_BUILTIN (__mips_isa_rev >= 1)
> +#define USE_FFSLL_BUILTIN (__mips_isa_rev >= 1)
> --
> 2.43.0.windows.1
--
Maxim Kuvyrkov
https://www.linaro.org
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